In the prior art, communication between a centralized computer host location and one or more peripheral locations for example, via standard telephone lines, has been secured in a variety of techniques. For example, one technique which employs some measure of hardware or software lock-out or data encryption, typically calls for the assignment of code numbers or identification numbers to allow the host computer to determine whether access is being attempted by a legitimate user or other.
Personal identification numbers (PINs) have also been employed alone or in tandem with other code or identification sequences, some dependent (the output of one device of circuit may be a function of one or more inputted code numbers), some independent. However, in some cases, the use of PINs may not eliminate the problem of eavesdropping by an unauthorized entity. In these cases a misappropriation of an authorized access code by an unauthorized individual can occur.
It has also been known to use enciphering devices to camouflage transmissions while such are exposed to unsecured transmission lines as well as deciphering devices to prepare the intended communication for use by the receiving device.
The use of combinations of hardware and software to act as security devices has resulted in the evolution of passkeys, authorization cards (credit card type with magnetic strip) and the like. Further to this, limitations as to specific terminal usage by specific users have grown in an effort to secure computer systems. Generally, in many cases, the responses to this security issue have resulted in some measure of inconvenience to the user, in the form of carrying the correct card and/or memorizing a series of passwords and/or having access to a portable security box device.
Other types of security criteria, such as fingerprint matching, handwriting matching and voice verification have also been incorporated into the construction of communications systems. Fingerprinting and handwriting verification techniques, however, have difficulties with the matching process. Voice verification usually involves a comparison of fixed speech templates to an inputted voice pattern with possible secondary or tertiary analyses performed if the comparison yielded marginal differences in the patterns.
Speech recognition systems, as opposed to voice verification systems have been available in the market for some time. In its infancy, speech recognition technology was directed toward integrated circuit designs an example of which is the integrated circuit design of NEC known as the K3 chip set. Unfortunately for the speech recognition industry it was constructed to be very sensitive to variations in speech. This sensitivity is the key to its usefulness in voice verification systems. The K3 chip set is equipped with speech templates to hold a digital representation of at least one uttered word. This chip set is also designed to compare that digital representation to another digital signal which is loaded into the chip set from a separate storage medium.
Further to this, voice verification has, in the past, required significant input time to convert the voice pattern to a mode which could be easily transmitted over standard telephone lines, with the transmission of one word requiring as much time as 60 seconds to fully transmit at normal transmission rates. This is largely due to the required byte sequencing with such systems.
Accordingly, it is an object of the invention to eliminate a need for a separate passkey, card or other ancillary hardware security items to protect against unauthorized use of a computer system.
It is another object of the invention to maintain security of a host controller of a computer system in a simple manner.
It is another object of the invention to enhance security of a computer system during an access phase of communication and, optionally, during data transmission.
It is another object of the invention to use voice verification techniques to obtain a secure communication system between a host computer and a plurality of remote user terminals.
It is another object of this invention to reduce the transmission time required to transmit a digital sequence corresponding to at least one spoken word.
It is another object of this invention to provide a voice verification capability which can be updated with each allowed access to a computer system employing this voice verification security provision.